Drive mechanism for electrical switches

ABSTRACT

A double-acting drive mechanism for actuating the contacts of an electrical switch between open and closed position includes a cylinder having a double-acting piston therein and a piston rod extending through one end of the cylinder for connection to the contact actuating mechanism of the switch. Each end of the cylinder is closed by a stationary member having a flanged portion provided with one or more circular rows of cartridge chambers serving as a magazine and which communicate with the corresponding end of the cylinder, and a latch-releasable springdriven rotary member carrying a firing pin is mounted on each end closure member for the cylinder for rotation in a step-by-step manner around the row of cartridge chambers so as to fire the cartridges in succession.

United States Patent [1 1 Strubin DRIVE MECHANISM FOR ELECTRICALSWITCHES [75] Inventor: Harald Strubin,Neuenhof,

Switzerland [73] Assignee: Brown Boveri & Company Limited, Baden,Switzerland [22] Filed: Sept. 8, 1972 [21] Appl. No.: 287,285

[30] Foreign Application Priority Data Sept. 23, 1972 Switzerland13843/72 [56] References Cited UNlTED STATES PATENTS 6/1965 PerryZOO/61.08 4/1969 Boop 200/82 R [451 Sept. 25, 1973 3,646,292 2/1972Barkan et al 200/82 B Primary Examiner-Harold Broome Att0rneyRalph E.Parker et al.

[57] ABSTRACT A double-acting drive mechanism for actuating the contactsof an electrical switch between open and closed position includes acylinder having a doubleacting piston therein and a piston rod extendingthrough one end of the cylinder for connection to the contact actuatingmechanism of the switch. Each end of the cylinder is closed by astationary member having a. flanged portion provided with one or morecircular rows of cartridge chambers serving as a magazine and whichcommunicate with the corresponding end of the cylinder, and alatch-releasable spring-driven rotary member carrying a firing pin ismounted on each end closure member for the cylinder for rotation in astepby-step manner around the row of cartridge chambers so as to firethe cartridges in succession.

9 Claims, 4 Drawing Figures DRIVE MEcHANlsMroa ELECTRICAL SWITCHES isimpinged upon alternatingly in both directions by ignited detonatinggas, the ignition being accomplished by spark plugs (German Patent1,287,677.). Also known is a pressure gas switch where the cut-off isaccomplished by arc quenching, and the drive by the ignition ofcartridges filled with explosives which are replenished by a magazineclip, similar to a self-loading rifle (German Patent 568,887). Theswitching-on is accomplished here by spring force. Finally, there isknown in view of the German published patent specification DT/AS1,118,316 a switch drive wherein the switch-on direction apiston ismoved by the ignition of cartridges in an explosion chamber, whereby thecar- .tridges are delivered by means of a guide-slide magazine.

The primary object of the present invention is to provide a more simplesolution where the transfer of cartridges by moving magazines is avoidedbut still providing a relatively large quantity of cartridges. The driveproposed by the invention is characterized by the features that bothends'of a cylinder which holds the driving piston, are closed off byflanged end membersdesigned to form a stationary cartridge magazine,whereby the. flanged endmembers are provided with a part that isrotatable by spring force, and which after the ignition of onecartridgecanalways be made ready to provide the next cartridge by thetransitory release of the spring-activated turning device,.the releasebeing controlled by the explosive gas, and that the rotatable part isprovided with a striker pin and a duct which guides the explosive gasesto the drive area.

The foregoing, aswell as other objects and advantages inherent in theinvention will becomemore apparent from the following detaileddescription of a preferred embodiment thereof and from the accompanyingdrawings wherein: v i

FIG. 1 shows the improved drive in longitudinal cross-section, V

FIG. 2 is also a cross-section which depicts avariation in a detail ofthe cartridge arrangement in'FIG. v1;

and a FIGS. 3 and 3a are sections along the cutting line A A, with FIG.3, 3a depicting the same cartridge arrangement as shown by FIG. 2.

With reference now to FIG. 1, the .double acting working piston 14 isseen to be located within cylinder 14a. Piston 14 is provided with apiston rod 14b,

connected to the contact mechanism of the switching apparatus which isnot shown in detail. Both ends of the piston cylinder 14a are closedoff,each with one flanged end member 10. Inside the flanged end members,spaces and 6 are provided which can have volumes of different sizes. Inthe species depicted, the space 5 located at the left end of cylinder14a which communicates with the left side of'pist'on I4 is larger sothat with the use of identical cartridges, theenergy of thrust, actingin this direction, i.e.,.towards the right,

will have a lesser effect (switch-on direction). The thrust space 6 forthe switch-off direction associated with the right end of cylinder 14aand the right side of piston 14 is kept smaller with the result that adesirable greater driving force of piston 14 and piston rod 14b to theleft is generated. The cartridges 11 are accommodated in bores providedin the flanged end members 10, located along a single pitch circle oralong two circles 1, 2 (FIG. 3). It will be advantageous in thisconnection, as shown by FIGS. 2 and 3, to arrange the bores of thesmaller'pitch circle 1 so as to lie between the bores of the largercircle 2, because in this manner a greater number of bores, andconsequently a greater number of cartridges 11 can be accommodated inthe flanged end members 10.

Mounted for rotation on a cylindrical projecting part 10a of each of theflanged end members 10 and which is coaxial with an extension of theaxis of cylinder 14a is a rotatable part 22 which is provided with aduct l2 which extends in a radial direction inwardly from the cartridgechamber 11a and terminates in a circumferentially extending passageway12a which is in constant communication with the spaces 5, 6 respectivelyby means of one or more bores 50, 6a through the wall of the mountingpart 10a. The rotatable part 22 is provided with a longitudinallyextending arm portion 22a which rotates in contact with the periphery ofthe flanged end member 10 and which is provided with a pivotally mountedlever 9 which, in the case of the embodiment depicted in FIG. 1, carriesa single firing pin 4 having a stroke along a path intersecting thepitch circle defining the positions of the circumferentially spacedcartridge chambers l'la.

In the case of the embodiment according to FIG. 2, the correspondinglever 9' is provided with two firing pins 4, 4 which are alignedrespectively with each of the two concentric pitch circles 1 and 2provided with the staggered circular rows of cartridge chambers 11a and11b in which the cartridge 11 are fired in alternation.

It will be noted that dummy holes 3 are located along each of the twopitch circles in alternation with the cartridge chambers l laand 11b sothat each time the firing pin lever 9 is actuated, one firing pin servesto detonatea cartridge along one pitch circle and the other firing pinenters a dummy hole 3 on the other pitch circle. 1

A magnetic system is utilized for effecting actuation of the firing pinlever 9, or 9' at each end of the cylinder 14a and flanged end member10. As depicted in FIG. 1, each of the two magnetic systems includes apermanent magnet 7 having an annular configuration which concentricallysurrounds the cylinder 14a and is supported by a radially extendingflange 14b. Each annular magnet 7 is provided with an annular pole shoe7a and includes an annular disc-shaped armature 8 carried by an annularsupport 25 which is slidable along and is guided by a cylindricalcontrol coil 26 surrounding and supported by cylinder so as to providefor movement of armature 8 between the lever-striking position depictedat the left end of FIG. 1 at which the cartridge 11 is fired, and aretracted position depicted at the right end of FIG. 1 against thecounter-action of a helical firing spring 24 located intermediate coil26 and magnet structure 7, 7a so as to lie in contact with the end ofthe pole shoe 7a. The magnetic flux produced by energization of coil 26is counter to that produced by the permanent magnet 7 itself so thatwhen coil 26 is not energized, the magnetic flux produced by magnet 7 isstrong enough to hold armature 8 in the retracted position away from thefiring pin lever 9, or 9. However, when the flux-weakening coil 26 isenergized, the force attracting armature 8 to the pole shoe 7a islessened to the extent that the counterforce stored by compression ofspring 24 is then sufficient to drive the support 25 and armature 8 sothat the latter strikes lever 9 or 9' and causes the firing pin 4 tostrike and detonate cartridge 11. The ensuing explosion gases passthrough the passageways 12, 12a and 50 into the chamber space and drivepiston 14 and its piston rod 14b from the left hand, full line positionat the left end of cylinder 14a depicted in FIG. 1 to the right hand,broken line position at the right end of cylinder 14a. As previouslyexplained, piston rod 14b is coupled to the switch contact actuatingmechanism and thus effects closing of the switch contacts.

As the pressure builds within the space 5 by the explosion gases, aportion of such gases passes outwardly through ducts 15 each of whichlead from the space 5 and terminate at one end of a bore containing atappet rod 8a which acts in the manner of a piston and drives againstarmature 8 forcing the latter to move in the opposite direction awayfrom lever 9 against a counter force of spring 24 which is thenre-compressed and reengage with pole 7a which then holds it in thisattracted position, the release current pulse applied to thefieldweakening coil 26 then having been terminated, until the nextfiring action takes place.

Also mounted on the rotatable part 22 is a casing 28 enclosing acompression spring 20 which exerts its force against a tappet rod 17aslidable within a bore 16 which communicates with the circularpassageway 12a. Connected to tappet rod 17a by means of a piston-likeguide member 29 slidable within casing 28. is a resilient pawl 17engageable with and controlling the operation of a latch lever, one endof this lever 18 being engageable with the pawl and the opposite endbeing arranged to engage in one of a circumferential array of grooves 21provided at the periphery of the end member 10, as shown more clearly inFIG. 3a.

As soon as piston 14 moves past ports 19 in the wall of cylinder 14a,the pressure of the explosion gases will drop at the driving side, e.g.,5, thus dropping the pressure within bore 16 and permitting the forcestored within compressed spring 20 to act through the pistonlike guidemembers 29 and shift tappet 17a and pawl 17 in the direction such as tocause a temporary rotation of the spring biased latch lever 18 torelease it from the particular groove 21 with which it has been engaged.This shifted position of the tappet 17a, guide 29 and pawl 17 isdepicted at the right end of FIG. 1.

A spirally coiled spring 23 is located in a recess b provided withineach of the end members 10 and surrounds the cylindrical portion 10a.The inner end of spring 23 is anchored to the portion 10a and the outerend of spring 23 is provided with a driving dog 23a which engages arecess 22b provided in the rotatable part 22. The driving spring 23 iswound by rotating the part 22 about the end member 10 with the latchlever 18 disengaged.

When latch lever 18 is momentarily actuated by the shifting movement ofpawl 17 so as to disengage the lever from a groove 21, the torque storedin the wound spring 23 will then cause the part 22 to rotate by one stepor pitch along the pitch circle of the cartridge chambers at whichinstant it is then stopped by engagement of the latch lever 18 in thenext adjacent groove 21. The pawl 17 and its associated structure willremain in the position depicted at the right end of FIG. 1 until thenext cartridge is fired from the left end of FIG. I, at which time, thepressure build-up within the space 5 will cause the tappet 17a, guide 29and pawl 17 to be shifted back to the position depicted at the left endof FIG. 1 in readiness to once again trip the latch lever 18 as soon aspiston 14 has been driven far enough into its cylinder 14a to expose theports 19 to the space 5.

As previously explained, the'operating arrangement for the cartridgemagazine structure at each end of cylinder 14a is alike with thepossible exception that the volume of space 5 is made somewhat greaterthan that of space 6 so as to provide a less forceful actuation of theswitch contacts to the contact-closed position as piston rod 14b isdriven from left to right as viewed in FIG. 1. The cartridges 11 areretained within their chambers by means of an annular ring 27 providedwith an annular groove or grooves 27a depending upon whether one or tworings of cartridges are utilized which receive and press against theends of the cartridges. Removal of ring 27 enables the cartridgemagazine structure to be re-filled simply and quickly. While the spaces5 and 6 have essentially the same diameter and length, the differencesin their respective volumes is attributable to the fact that piston rod14b passes through the space 6 thus reducing its effective volumeaccordingly.

I claim:

1. In a double-acting drive mechanism for actuating the contacts of anelectrical switch between their closed and open positions, thecombination comprising a cylinder, a double-acting piston operablewithin said cylinder, a flanged end member for and closing off each endof said cylinder, the flanged portion of each said end member beingprovided with at least one circular row of circumferentially spacedchambers constituting a stationary magazine for receiving cartridgeswhich upon detonation produce explosion gases for driving said pistonfrom one end of said cylinder to the other, a piston rod extendingthrough one of said end members and which is connectible to the switchcontact actuating means, duct means establishing an explosion gas flowpath between each of said cartridge chambers and the corresponding endof said cylinder, cartridge firing means including a firing pin mountedon said end member for rotation in a step-by-step manner along said rowof cartridge chambers for effecting consecutive firing of thecartridges, actuating means for said firing pin, spring means forimparting a continuous torque to said rotary cartridge firing means, alatching device restraining rotation of said cartridge firing means ateach cartridge chamber position, and means releasing said latchingdevice after each cartridge is fired whereby said rotary cartridgefiring means automatically steps to the next cartridge firing position.

2. A double-acting drive mechanism as defined in claim 1 for actuatingthe contacts of an electrical switch wherein each of said flanged endmembers is provided with a pair of concentric circular rows ofcircumferentially spaced cartridge chambers, the cartridge chambers ofone row being circumferentially staggered with respect to the cartridgechambers of the other row, and wherein said cartridge firing means isprovided with a firing pin serving each row of cartridge chambers.

3. A double-acting drive mechanism as defined in claim 1 for actuatingthe contacts of an electrical switch wherein said releasable latchingdevice for restraining rotation of said cartridge firing means at eachcartridge chamber position includes operating means therefor actuated bythe explosion gases after said piston has been driven for apredetermined distance within its cylinder.

4. A double-acting drive mechanism as defined in claim 1 for actuatingthe contacts of an electrical switch wherein said firing pin is mountedon a lever and wherein said actuating means for said firing pin isconstituted by a magnetic assembly including a stationary annularholding magnet surrounding said cylinder, an annular armature memberalso surrounding said cylinder and which is mounted for movementparallel to itself between said holding magnet and a position strikingsaid firing pin lever, and a striker spring engaging said armaturemember for driving the latter against said firing pin lever whenreleased from said magnet.

5. A double-acting drive mechanism as defined in claim 4 for actuatingthe contacts of an electrical switch wherein said holding magnet is ofthe permanent type and which further includes a release coil associatedtherewith, said release coil when energized producing a magnetic fluxcounter to the magnetic flux produced by said permanent magnet and whichserves to weaken the effective attractive force and release saidarmature member.

6. A double-acting drive mechanism as defined in claim 4 for actuatingthe contacts of an electrical switch and which further includes meansactuated by the explosion gases for resetting said armature member intoengagement with said holding magnet and simultaneously storing a forcein said striker spring.

7. A double-acting drive mechanism as defined in claim 1 for actuatingthe contacts of an electrical switch and wherein said duct meansestablish a flow path for the explosion gases from said cartridgechambers to the end of said cylinder includes a passageway leadingthrough said rotary cartridge firing means into a space provided in saidend member and which communicates with the end of said cylinder.

8. A double-acting drive mechanism as defined in claim 7 for actuatingthe contacts of an electrical switch wherein the effective volumes ofthe spaces provided respectively in said end members differ from oneanother so as to provide correspondingly different driving forces onsaid piston for its opposite directions of movement.

9. A double-acting drive mechanism as defined in claim 1 for actuatingthe contacts of an electrical switch wherein said latching deviceincludes a latch lever mounted on said rotary cartridge firing means,one end of said lever being engagcable in each of a circular row ofcircumferentially spaced grooves provided in said end member, and theother end of said lever being actuatable by a pawl which in turn isactuated in response to the pressure created by the explosion gases. 4=1: =0 1:

1. In a double-acting drive mechanism for actuating the contacts of anelectrical switch between their closed and open positions, thecombination comprising a cylinder, a double-acting piston operablewithin said cylinder, a flanged end member for and closing off each endof said cylinder, the flanged portion of each said end member beingprovided with at least one circular row of circumferentially spacedchambers constituting a stationary magazine for receiving cartridgeswhich upon detonation produce explosion gases for driving said pistonfrom one end of said cylinder to the other, a piston rod extendingthrough one of said end members and which is connectible to the switchcontact actuating means, duct means establishing an explosion gas flowpath between each of said cartridge chambers and the corresponding endof said cylinder, cartridge firing means including a firing pin mountedon said end member for rotation in a step-by-step manner along said rowof cartridge chambers for effecting consecutive firing of thecartridges, actuating means for said firing pin, spring means forimparting a continuous torque to said rotary cartridge firing means, alatching device restraining rotation of said cartridge firing means ateach cartridge chamber position, and means releasing said latchingdevice after each cartridge is fired whereby said rotary cartridgefiring means automatically steps to the next cartridge firing position.2. A double-acting drive mechanism as defined in claim 1 for actuatingthe contacts of an electrical switch wherein each of said flanged endmembers is provided with a pair of concentric circular rows ofcircumferentially spaced cartridge chambers, the cartridge chambers ofone row being circumferentially staggered with respect to the cartridgechambers of the other row, and wherein said cartridge firing means isprovided with a firing pin serving each row of cartridge chambers.
 3. Adouble-acting drive mechanism as defined in claim 1 for actuating thecontacts of an electrical switch wherein said releasable latching devicefor restraining rotation of said cartridge firing means at eachcartridge chamber position includes operating means therefor actuated bythe explosion gases after said piston has been driven for apredetermined distance within its cylinder.
 4. A double-acting drivemechanism as defined in claim 1 for actuating the contacts of anelectrical switch wherein said fiRing pin is mounted on a lever andwherein said actuating means for said firing pin is constituted by amagnetic assembly including a stationary annular holding magnetsurrounding said cylinder, an annular armature member also surroundingsaid cylinder and which is mounted for movement parallel to itselfbetween said holding magnet and a position striking said firing pinlever, and a striker spring engaging said armature member for drivingthe latter against said firing pin lever when released from said magnet.5. A double-acting drive mechanism as defined in claim 4 for actuatingthe contacts of an electrical switch wherein said holding magnet is ofthe permanent type and which further includes a release coil associatedtherewith, said release coil when energized producing a magnetic fluxcounter to the magnetic flux produced by said permanent magnet and whichserves to weaken the effective attractive force and release saidarmature member.
 6. A double-acting drive mechanism as defined in claim4 for actuating the contacts of an electrical switch and which furtherincludes means actuated by the explosion gases for resetting saidarmature member into engagement with said holding magnet andsimultaneously storing a force in said striker spring.
 7. Adouble-acting drive mechanism as defined in claim 1 for actuating thecontacts of an electrical switch and wherein said duct means establish aflow path for the explosion gases from said cartridge chambers to theend of said cylinder includes a passageway leading through said rotarycartridge firing means into a space provided in said end member andwhich communicates with the end of said cylinder.
 8. A double-actingdrive mechanism as defined in claim 7 for actuating the contacts of anelectrical switch wherein the effective volumes of the spaces providedrespectively in said end members differ from one another so as toprovide correspondingly different driving forces on said piston for itsopposite directions of movement.
 9. A double-acting drive mechanism asdefined in claim 1 for actuating the contacts of an electrical switchwherein said latching device includes a latch lever mounted on saidrotary cartridge firing means, one end of said lever being engageable ineach of a circular row of circumferentially spaced grooves provided insaid end member, and the other end of said lever being actuatable by apawl which in turn is actuated in response to the pressure created bythe explosion gases.